The invention relates generally to power conversion control systems.
A typical power distribution system comprises a power conversion module with a DC side and an AC side, a grid electrically coupled to the AC side of the power conversion module, a power distribution unit electrically coupled to the DC side of the power conversion module, and a conversion control system for performing control of the power conversion module. Conversion control systems typically comprise phase-locked-loop (PLL) circuits for generating synchronized phase and frequency signals.
A PLL circuit is typically a closed loop circuit and works well under substantially steady operating conditions of the power distribution system. However, when a transient condition, such as Low voltage ride through (LVRT), Zero Voltage Ride Through (ZVRT), or High Voltage Ride Through (HVRT) occurs, the grid voltage has a significant phase jump, and the PLL circuit may fail to provide a fast enough response to prevent reversed flow of active power or may result in inappropriate reactive power control in the power system.
It would be desirable to have an improved power conversion control system and method with fast responses to transient conditions.